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Wednesday, November 30, 2016

Both Andrea and Paul had already experienced a couple of hours learning snowplough and were able to make very wobbly and insecure long turns on the nursery slope. They were both able to use the plough and stem their skis – but clearly this standard method of skiing was also leading towards imposing some serious limitations. Rather than continue this process I decided to move them in another direction and teach skating and dynamics – the true fundamental principles of skiing. As luck would have it Andrea turned out to have been a keen skater in her childhood so her skills could be immediately put to good use. Paul in comparison was put at a great disadvantage but could use Andrea as a clear reference for the coordination and skills he needed to develop.

The first video shows Andrea progressing from skating turns to parallel turns and doing so with a clear understanding of how it works – by using grip from the ski through the inside edge of the foot and use of the muscles on the inside of the leg to move the centre of mass out of balance – to accelerate it into the turn. We did both basic skating exercises and dynamics exercises to get there…

There are two fixed pages can be accessed from the menu the top of the page that show the details of the skating and dynamics in more depth

Paul was struggling with the coordination needed through the feet, legs and upper body to stay in control of things so it was better for him just to get used to sliding straight and then when secure and slowing towards the end attempt a turn to finish. Plenty of practice at this would build both confidence and competence rapidly – the key is getting used to accelerations and being able to relax and feel the body and then the effects that movements bring from the skis.

Tuesday, November 29, 2016

Michel, Eric, Veerle and Jennifer received a rapid crash course in dynamics in Tignes today. Most intermediate skiers are stuck forever on an uncomfortable plateau with their skiing and they also find that hearing the same instruction that they heard before doesn’t lead to great changes taking place. Time on skis is often limited – so with all of this in mind I decided to take a chance by throwing everyone in the deep end – almost literally. The objective was to attempt to generate a profound change in understanding, mindset and movement pattern all in the space of about an hour.

Dynamics

The key to creating such a huge shift is “dynamics”. There is a fixed page on dynamics here http://skiinstruction.blogspot.fr/p/dynamics.html After a rapid explanation of the difference between dynamics and “balance” we carried out some static exercises to show that it is the acceleration of the centre of mass down and into a turn that generates pressure on the outside ski. Acceleration in physics is the exact opposite of balance. The skier needs to learn to fall over laterally to the skis – as if on a motorbike. The ski works by lifting the skier back up. With a bike there is a limit as to how far over you can fall and hope to get back up – but on skis the grip and lifting effect only increases as you fall harder. The limit of the skier is actually the ability to increase the dynamic range – most will only manage about 15 degrees compared to 80 degrees for a top racer. It’s a mental and emotional issue too – because falling downhill laterally to the skis is scary – until you know how it works.

There wasn’t time for feedback and correction but everyone could feel the difference – Eric noticing that his legs weren’t getting as tired as usual. Veerle was keeping her weight on her lower ski and stemming the top ski outwards – negating the effort to use dynamics – but she was aware of this and needs time to work on changing it. (plus a few simple exercises).

Eric asked about pole use so I rapidly explained that as with a motorbike the body goes down into a turn and up out of it – this is a universal principle even if ski schools teach the opposite. The pole is only needed as a light touch for feedback when falling into a turn and it’s the movement of the body which does this – not the arm. This actual issue is referred to as timing.

Both Eric and Michel needed to work on avoiding being stuck in the vertical plane (to gravity) and to try to adjust continuously to achieve perpendicularity to the slope.

Jennifer didn’t need as much feedback at this stage and was quietly getting on with it.

Eric asked about skiing with the knees/feet together so I demonstrated the “pivot” and how two footed skiing works with the skis slipping into the turn from the top edges. There is a fixed page here also (at the top of the blog) on the Pivot with exercises shown on video.

Monday, November 28, 2016

Today was undoubtedly the last opportunity to swim in cold water – due to the skiing season getting underway and the man made lakes being due to be emptied for the winter. The temperature registered minus 1.9 degrees centigrade on my Infra Red sensor – but that seems highly unlikely. I’d guess that zero is more like the reality. The ground next to the lake was still white with frost even in late afternoon.

I’m now sure that this is my limit because large areas of skin have experience an Ice Burn almost identical to a sun burn in feeling. My nose also ran for about 12 hours after I stopped shivering – so I wouldn’t want to push things further than this. All the same there was no difficulty staying in the water and I could have remained longer. Doing the crawl with the head submerged was challenging and encouraged me to stop at just about the right moment. I need to find out about how to protect the skin now and whether or not it can adapt as well as the nervous system adapting and brown fat being generated. There was no shivering until leaving the water but the force of the shivering to generate body heat shows that brown fat is still in short supply here!

Monday, November 21, 2016

Swimming at zero degrees centigrade is probably best left to the ducks – who seem not to mind the low temperature at all. It seems like nobody has told this one here that it’s time to migrate.

Cold exposure – when only affecting the skin and not allowed to induce hypothermia – has a powerful effect on the hormonal systems within the body. Perhaps the most interesting is the production of the hormone “irisin” which converts white fat into brown fat. Brown fat has the special quality of producing heat from mitochondria without any mechanical action – but there is another hidden value. Brown fat acts as a mitochondrial safety valve – burning off excess ATP (energy molecule) and preventing excessive build up of free radicals associated with genetic mutations and aging. Rats for example don’t have this mitochondrial mechanism and they live for about four years. Pigeons, which have a similar metabolic energy need have a strong mitochondrial safety valve and can live for about 36 years.

The hypothalamus in the brain is effectively rewired through cold exposure and this alters the metabolic system considerably as it controls body temperature and the thyroid. So in addition to a ketogenic (high fat) diet cold exposure is a bit like therapy for the thyroid – though a daily drop of 15% Lugol’s solution does wonders too (15% iodine and 30% potassium iodide). Another thing that adaption to the cold brings through the nervous system is a huge reduction in pain sensitivity. All of this of course is very useful as humanity has spent most of its existence in ice. Even today we are in an Ice Age and most people don’t realise it due to political propaganda. Our current Ice Age has been on the go for 2.8 million years.

Perhaps my main interest in cold exposure however is the vagus nerve. This nerve controls a large chunk of the autonomic nervous system – that is organs over which there is no conscious control. The vagus nerve is strongly toned by the cold exposure and the surge of hormones including adrenaline – corresponding to the cold shock received. Adaptation is progressive but rapid over about 10 exposures and the effect of the vagus nerve on the heart can be measured with a simple heart rate monitor and a cardiac variability app on a phone. Nothing improves (increases) heart rate variability faster than cold exposure.

Two winters ago when just starting the ketogenic diet I noticed my maximum heart rate slowly modifying. Most of us are used to seeing it very slowly declining with age and that’s what I saw too – until then. From two months after adopting a high fat diet the max heart rate began to creep upwards. This is so ironic because for most of my life I’d heard the nonsense that fat causes cardiovascular congestion. Up it continued – from 172 to 174, to 176 and 182 to 186 and finally to 191. This was all when running sprint intervals up a steep hill . Meanwhile along with the cold exposure, ketogenic diet and exercise I added vitamin B3 (nicotinic acid) which cleans out the arteries – and vitamin k2 at a one tenth ratio to vitamin D. Today I went back to the sprint intervals for the first time in two years and gradually warmed up with the first interval at 2.1k, the second at 5.6k and the third at 9.1k. The final sprint saw a smooth peak in heart rate at 202 bpm. Well the last time I saw that was in my late 20s so that’s interesting! It wasn’t an equipment artifact – that’s very easy to spot. I know that cardiac emergency patients – with a real problem, can reach over 400 bpm and survive so the 202 is still very normal. Author Sally Edwards – the lady who effectively wrote the book on this subject for Polar states now that you have a max heart rate for life and it only reduces if you are sedentary. I’d like to offer another explanation – it only reduces if you eat inappropriately no matter how much you exercise.